Multiply Branched Polymers

Solid line. Theoretical random scission L =. 72 Dashed line and A. Experimental for branched polymer DYNF molecular weight > 9100, 3.7 CHs per 100 CH, (16, 27) Vertical scale is to he multiplied by 2... 

The versatile inclusion phenomena exhibited by the family of cyclodextrin (CD) macrocycles have been harnessed to produce supramolecular dendrimers and hyper-branched polymers. An early demonstration of exorecognition that resulted in an electroresponsive supramolecular dendrimer was published by Kaifer and coworkers in 1997 (Scheme 2). The group produced a series of polypropylene imine (PPI) " dendrimers (from the first to the fourth generation) that were decorated with cobaltacene residues at the periphery. In their multiply charged state (2), the... 

In order to accoimt for the fact that the molecular size of branched polymers is affected by both the molecular weight and the branching structure, Mendelson etal. [114] multiplied by the branching factor g, the mean square radius of gyration ratio defined by Eq. 2.16, to... 

A few points should be noted before discussion of the mote complex derivatives. The addition of substituent groups is controlled by reaction conditions. Depending on the conditions, the reactive sites on a given monomer will be mono substituted, multiply substituted, or not substituted. Therefore, the production (reaction) parameters dictate the final properties of a polymer. Complex derivatives which create fiee hydroxyl ends, such as a hydro alkyl addition, can cause polymerization with new chains forming off the original substituent groups. These branches will... 

With the rapid expansion in controlled radical polymerisation chemistry, for example, atom-transfer radical-polymerisation (ATRP) [47], it is clear that combinations with the inorganic polyphosphazene backbone, and its many unique properties, can add extra dimensions and multiply the opportunity for new hybrid materials. As the inorganic component in such polymers is low, often below 5%, the resultant polymers often possess the solution, chemical and biological properties of the attached organic component and can, in effect, be viewed as highly branched versions on an inorganic (potentially degradable) backbone. 

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